Reproduction of Euastacus bispinosus Clark (Decapoda:Parastacidae), and trends in the reproductive characteristics of freshwater crayfish

1995 ◽  
Vol 46 (2) ◽  
pp. 485 ◽  
Author(s):  
JA Honan ◽  
BD Mitchell
Keyword(s):  
Breeding Season ◽  
Generation Time ◽  
Carapace Length ◽  
South Australia ◽  
River System ◽  
Reproductive Rate ◽  
Freshwater Crayfish ◽  
Size At Sexual Maturity ◽  
Western Victoria ◽  
Potential Reproductive Rate

The reproductive biology of Euastacus bispinosus populations was studied in a river and a creek of the Glenelg River system in south-western Victoria, and a small coastal creek in south-eastern South Australia. Females produced eggs in the first breeding season after maturation of their gonopores. At the Victorian sites, E. bispinosus spawned in early May, carrying eggs for about seven months before hatching and juvenile release in October-December. At least 95% of mature females at each Victorian site carried eggs during the breeding season. Mature females had relatively broader abdomens than did males and carried between 63 and 812 eggs. The number of eggs carried was linearly related to both occipital carapace length and abdomen width. The South Australian population differed from the Victorian populations in having a smaller mean size at sexual maturity for females (occipital carapace length 58 mm compared with 85-86 mm in Victoria), a higher proportion (17%) of gonopore abnormalities (< 1% in Victoria), and relatively wider abdomens (which continued to broaden after maturity). Euastacus bispinosus is a winter brooder and has a long generation time and low potential reproductive rate, characteristics it shares with Astacopsis and Parastacoides species, and members of the Astacidae. Other crayfish species (e.g. Cherax species and members of the Cambaridae) are summer brooders and tend to have a high potential reproductive rate and short generation time.

Reproductive biology of the slipper lobster Scyllarides deceptor (Decapoda: Scyllaridae) along the southern Brazilian coast

2008 ◽  
Vol 88 (7) ◽  
pp. 1433-1440 ◽  
Author(s):  
Gabriela Oliveira ◽  
Andrea S. Freire ◽  
Paulo R.K. Bertuol
Keyword(s):  
Reproductive Biology ◽  
Breeding Season ◽  
Sexual Maturity ◽  
Egg Size ◽  
Carapace Length ◽  
Sampling Period ◽  
Late Winter ◽  
Brazilian Coast ◽  
Rocky Bottom ◽  
Size At Sexual Maturity

The reproductive biology of Scyllarides deceptor was studied along the southern Brazilian coast (27°S 48°W) from December 2002 to December 2003. Samples were collected monthly at Xavier Island, where animals were caught and marked. Fecundity and egg size were estimated from ovigerous females caught also in two adjacent islands, Arvoredo and Aranhas. A total of 98 females was recorded at Xavier Island during the sampling period, 24 of these were recaptured and presented time-at-liberty ranging from 14 to 297 days. Ovigerous females were observed during spring and summer, with the moulting period lasting from late winter to spring. Size at sexual maturity was assessed from 66 females caught during the breeding season and estimated in 85.33 mm of carapace length (CL). Mean fecundity of S. deceptor was estimated in 191,262 eggs (±17,811, SE) for females, on average, 94.74 mm long (±1.86 mm SE) (CL). Fecundity was significantly related to CL (R2 = 0.90) Mean egg size was 0.67 mm (±0.005 mm SE) and did not correlate significantly to CL (P = 0.78). The rocky bottom of Xavier Island was favourable for reproduction, presenting shelter and foraging grounds for the ovigerous females. For management purposes, our results suggest the closure of the S. deceptor fishery from November to January and the capture-size of females to be restricted to animals larger than 90 mm (CL).

scholarly journals A comparison of the allometric growth in Uca leptodactyla (Crustacea: Brachyura: Ocypodidae) from two subtropical estuaries

2004 ◽  
Vol 84 (4) ◽  
pp. 733-735 ◽  
Author(s):  
Rosana Carina Flores Cardoso ◽  
Maria Lucia Negreiros-Fransozo
Keyword(s):  
Growth Pattern ◽  
Sexual Maturity ◽  
Carapace Length ◽  
Brazilian Coast ◽  
Allometric Growth ◽  
Size At Sexual Maturity ◽  
Subtropical Estuaries ◽  
Habitat Similarity

The allometric growth of Uca leptodactyla from two distinct subtropical estuaries on the Brazilian coast was evaluated concerning its growth pattern and size at onset of sexual maturity. Females attained maturity at similar sizes in both sites (4·1 mm of carapace length in Indaiá and 4·2 mm in Ubatumirim), while males differed slightly. They reached the size at sexual maturity of 5·3 mm of carapace length in Indaiá and 4·6 mm in Ubatumirim. Growth pattern is usually similar among crabs from distinct sites while size at sexual maturity is frequently different. However, in the case of U. leptodactyla it did not occur, probably due to the strong habitat similarity and intrinsic features of this species.

Distribution of Biomass, Nitrogen, Phosphorus and Other Nutrients in Banksia marginata and B. ornata Shoots of Different Ages After Fire.

1986 ◽  
Vol 34 (6) ◽  
pp. 709 ◽  
Author(s):  
RH Groves ◽  
PJ Hocking ◽  
A Mcmahon
Keyword(s):  
National Park ◽  
Dry Matter ◽  
Lateral Roots ◽  
South Australia ◽  
Distribution Patterns ◽  
Nutrient Accumulation ◽  
Nitrogen And Phosphorus ◽  
Vegetative Organs ◽  
Western Victoria ◽  
Nitrogen Phosphorus

The heathland form of Banksia marginata Cav. regenerates rarely from seed but commonly by resprout- ing from buds on lateral roots, whereas Banksia ornata F. Muell. regenerates only from seed, usually released after fire. The two species co-occur in heath vegetation on nutrient-poor soils in south-eastern South Australia and western Victoria. Shoots were sampled from stands of B. marginata aged from 1 to 25 years and of B. ornata aged from 1 to 50+ years after fire in the Little Desert National Park, western Victoria. B. marginata, the resprouter, distributed a greater proportion of the total shoot dry matter and content of all nutrients to vegetative growth over its shorter life span than B. ornata, the non-sprouter. About 50% of the total phosphorus in B. ornata shoots at 50+ years was present in cones (including seeds) compared with only about 20% in B. marginata shoots at a comparable stage of senescence (25 years). This difference between the species was also true to a lesser degree for nitrogen. There were considerable differences between other nutrients in their distribution patterns in shoots. Nutrients could be grouped together on the basis of distribution in shoots more satisfactorily than on presumed physio- logical roles. Stems were major sites of nutrient accumulation in both species. The content of a particular nutrient in seeds as a proportion of the content in the living parts of the shoot ranged from 0.03% (Na, Mn) to 2.0% (P) in B. marginata, and from 0.3% (Na) to as high as 31% (P) in B. ornata. Concen- trations of all nutrients except sodium were much higher in seeds than in the woody cones or vegetative organs of both species; seeds of B. ornata were particularly rich in calcium and manganese. We conclude that the different patterns of distribution of biomass and nutrients, especially nitrogen and phosphorus, within shoots of the two species reflect their different regenerative modes after fire. Introduction Phosphorus and, to a lesser extent, nitrogen limit the growth of sclerophyllous shrubs on nutrient-poor soils in southern Australia

scholarly journals Life Tables of Two-Spotted Spider Mite Tetranychus urticae Koch (Acari: Tetranychidae) and its Predator Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae)

1970 ◽  
Vol 16 ◽  
pp. 1-10 ◽  
Author(s):  
M Fazlul Hoque ◽  
W Islam ◽  
M Khalequzzaman
Keyword(s):  
Tetranychus Urticae ◽  
Generation Time ◽  
Development Time ◽  
Phytoseiulus Persimilis ◽  
Reproductive Rate ◽  
Finite Capacity ◽  
Net Reproductive Rate ◽  
Wide Range ◽  
The Mean ◽  
Capacity For Increase

Life table of Tetranychus urticae and Phytoseiulus persimilis on bean leaflets were studied under laboratory conditions in three seasons. For T. urticae the development time from egg to adult varied from 7 to 24 days and the highest immature mortality was 78.70 % in winter. Eggs laid by females were 88.1 eggs in autumn and 70.6 eggs in summer season. The gross reproductive rate (GRR) was the highest (65.51) in autumn and 52.50 in summer. The net reproductive rate (Ro) was the highest (15.862) in autumn and 8.916 in summer. The intrinsic rates of increase (rm) and finite capacity for increase (λ) reached maximal values (0.1873 and 1.206) in autumn, whereas minimal values (0.056 and 1.058) were in winter season. The mean generation time (T) was the shortest in summer and double (3.701) days in autumn. The development time of P. persimilis from egg to adult varied from 5 to 14 days. The highest immature mortality was 60% in summer. Eggs laid by females were 39.4 eggs in autumn and 30.2 eggs in summer. The gross reproductive rate (GRR) was the highest (31.4) in autumn and 24.0 in summer. The net reproductive rate (Ro) was the highest (10.573) in autumn and 8.460 in winter. The intrinsic rates of increase (rm) and finite capacity for increase (λ) reached maximal values (0.1823 and 1.200) in summer, whereas minimal values (0.1025 and 1.108) were in winter. The mean generation time (T) was the shortest in summer. The results suggested that P. persimilis could develop and reproduce within a wide range of temperatures. Key words: Tetranychus urticae, Phytoseiulus persimilis, immature mortality, intrinsic rates of increase, reproductive rate, Survival  DOI:10.3329/jbs.v16i0.3733 J. bio-sci. 16: 1-10, 2008

Life cycle and calculation of the intrinsic rate of natural increase of two bacterivorous nematodes, Panagrolaimus sp. and Poikilolaimus sp. from chemoautotrophic Movile Cave, Romania

Nematology ◽  
2007 ◽  
Vol 9 (2) ◽  
pp. 271-284 ◽  
Author(s):  
Daniel Muschiol ◽  
Walter Traunspurger
Keyword(s):  
Life Cycle ◽  
Body Length ◽  
Generation Time ◽  
Microbial Mats ◽  
Somatic Growth ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Net Reproductive Rate ◽  
Movile Cave

AbstractThe life cycle and somatic growth of two bacterivorous nematodes, Panagrolaimus sp. and Poikilolaimus sp., isolated from chemoautotrophic microbial mats in Movile Cave, Romania, were studied in monoxenic cultures at 20°C with Escherichia coli as the food source. A method is described that allows simultaneous investigation of the somatic growth pattern, age-specific fecundity, and age-specific mortality of single individuals with high accuracy. Somatic growth curves of the species are presented. During juvenile development, both species showed a strict linear increase in body length, whereas body weight increased exponentially. Growth was continuous without lag phases. The relationships between fresh weight, W (μg), and body length, L (mm), were W = 1.6439L2.7672 for Poikilolaimus sp. and W = 0.2085L4.0915 for Panagrolaimus sp. Life tables and fecundity schedules for the two species are presented. In addition, demographic parameters were calculated. For Panagrolaimus, the intrinsic rate of natural increase (rm), calculated according to the Lotka equation, was 0.309, the net reproductive rate (R0) 64, the mean generation time (T) 13.8 days and the minimum generation time (Tmin) 9.5 days. The corresponding values for Poikilolaimus were rm = 0.165, R0 = 108, T = 26.2 and Tmin = 19.5. Panagrolaimus produced fewer progeny than Poikilolaimus during its life but exhibited faster population growth due to its faster maturation. It showed a distinct post-reproductive period, whereas Poikilolaimus remained fertile until death.

scholarly journals Phytophagy of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae) fed on prey and Brassicaceae

2017 ◽  
Vol 77 (4) ◽  
pp. 703-709 ◽  
Author(s):  
J. F. J. Grigolli ◽  
M. M. Kubota Grigolli ◽  
D. G. Ramalho ◽  
A. L. Martins ◽  
A. M. Vacari ◽  
...  
Keyword(s):  
Generation Time ◽  
Reproductive Rate ◽  
Egg Mass ◽  
Reproductive Parameters ◽  
Net Reproductive Rate ◽  
Laboratory Rearing ◽  
Males And Females ◽  
The Mean ◽  
Heteroptera Pentatomidae ◽  
Alternative Diet

Abstract The purpose of this study was to investigate the development and reproduction of the zoophytophagous predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) fed kale, broccoli and cabbage affects its. Nymphs and adults of this predator were fed on larvae of Plutella xylostella (L.) (Lepidoptera: Plutellidae) as prey with kale, cabbage, or broccoli. In the nymph period, the duration and prey consumption were similar with all the Brassicacea cultivar. However, nymph viability was higher for predators with broccoli leaves. The mean weight of 5th-instar nymphs, newly emerged females and the sex ratio were similar among the Brassicacea cultivars, while newly emerged males were heavier with kale and broccoli leaves. The supply of broccoli leaves resulted in greater oviposition, higher number of eggs per egg mass and longer longevity of P. nigrispinus males and females. Furthermore, the consumption of P. xylostella larvae by adult predators was higher with these cultivars. The net reproductive rate (R0) and mean generation time (T) were highest for predators with prey and broccoli leaves. The reproductive parameters of P. nigrispinus were enhanced when fed on P. xylostella larvae with and broccoli leaves, which can be an alternative diet in laboratory rearing of this predator.

Delineation of conservation units in an endangered marsupial, the southern brown bandicoot (Isoodon obesulus obesulus), in South Australia/western Victoria, Australia

2014 ◽  
Vol 62 (5) ◽  
pp. 345 ◽  
Author(s):  
You Li ◽  
Melanie L. Lancaster ◽  
Susan M. Carthew ◽  
Jasmin G. Packer ◽  
Steven J. B. Cooper
Keyword(s):  
Conservation Management ◽  
Conservation Status ◽  
South Australia ◽  
Disjunct Distribution ◽  
Conservation Units ◽  
Evolutionarily Significant Units ◽  
Population Analyses ◽  
High Conservation ◽  
Western Victoria ◽  
Evolutionary Lineages

Conservation programs for threatened species are greatly benefiting from genetic data, for their power in providing knowledge of dispersal/gene flow across fragmented landscapes and for identifying populations of high conservation value. The endangered southern brown bandicoot (Isoodon obesulus obesulus) has a disjunct distribution range in South Australia, raising the possibility that populations of the subspecies may represent distinct conservation units. In the current study, we used a combination of 14 microsatellite and two mitochondrial sequence markers to investigate the phylogeography and population structure of I. o. obesulus in South Australia and south-western Victoria, with the aim of identifying any potential evolutionarily significant units and management units relevant to conservation management. Our phylogenetic/population analyses supported the presence of two distinct evolutionary lineages of I. o. obesulus. The first lineage comprised individuals from the Mount Lofty Ranges, Fleurieu Peninsula and Kangaroo Island. A second lineage comprised individuals from the south-east of South Australia and south-western Victoria. We propose that these two lineages represent distinct evolutionarily significant units and should be managed separately for conservation purposes. The findings also raise significant issues for the national conservation status of I. o. obesulus and suggest that the current subspecies classification needs further investigation.

ALLOMETRY OF THE SECONDARY SEXUAL CHARACTERS OF THE SHORE CRAB PACHYGRAPSUS TRANSVERSUS (GIBBES, 1850) (BRACHYURA, GRAPSIDAE)

Crustaceana ◽  
1999 ◽  
Vol 72 (9) ◽  
pp. 1051-1066 ◽  
Author(s):  
Maria Lucia Negreiros-Fransozo ◽  
Augusto Flores
Keyword(s):  
Growth Phase ◽  
Carapace Length ◽  
Shore Crab ◽  
Female Size ◽  
Allometric Growth ◽  
Secondary Sexual Characters ◽  
Size At Sexual Maturity ◽  
Reproductive Females ◽  
Crab Stage ◽  
Secondary Sexual

AbstractThe allometric growth of secondary sexual characters in Pachygrapsus transversus is investigated from the 2nd crab stage onward. Clear sexual dimorphism is restricted to abdominal morphology, but ANCOVA analyses showed that chelae become larger in males and the carapace becomes wider in females. Size at the puberty moult in both sexes was estimated using Somerton's computer techniques. Mature II analyses applied to bi-log gonopod length vs. carapace length relationships indicated a puberty moult at 5.0 mm in males. In females, Mature I analyses detected the overlapping growth phase lines in bi-log carapace length vs. abdomen width scatterplots. Fitting the logistic equation provided an estimate of 50% maturity at 5.5 mm. The regression lines separate young and resting individuals from the potentially reproductive females, but they do not separate young from adult crabs. Year-round monthly samples showed that the proportion of small adult-like females is higher during the breeding season. After breeding, females may moult to a young-like morphotype, as observed in controlled laboratory conditions. Moulting to a resting condition splits smaller mature females into different "growth phase" lines. Therefore, estimates of female size at sexual maturity by means of abdomen allometric growth analyses are inadequate in this species. El crecimiento alometrico de los caracteres sexuales secundarios de Pachygrapsus transversus ha sido investigado desde el segundo estadio pos-larval. El dimorfismo abdominal es la unica caracterostica que permite distinguir claramente los sexos, pero los analisis de covarianza aplicados a las regresiones obtenidas demuestran que las quelas se vuelven m as grandes en machos y que el caparazon se vuelve mas ancho en hembras. La talla en que ambos sexos alcanzan la maturidad sexual ha sido estimada atraves de las tecnicas de Somerton. La aplicacion del programa Mature II a la regresion bi-log entre el largo del caparazon y el largo del gonopodo indica que la muda de la pubertad de los machos ocurre a los 5,0 mm. En las hembras, el programa Mature I detecto la sobreposicion de loneas de regresi on en los diagramas de dispersion de la regresion bi-log entre el largo del caparazon y el ancho del abdomen. Del ajuste de la ecuacion logostica se obtiene que 50% de las hembras son sexualmente adultas a los 5,5 mm. Estas rectas de regresion separan las hembras con potencial reproductivo de los indivoduos j ovenes y aquellos en reposo sexual. Sin embargo, las rectas no separan jovenes de adultos. Muestreos mensuales a lo largo de un ano indican que la proporcion de hembras de talla puberal con morfologia adulta es mas elevada durante el peroodo reproductivo. Despues de la reproduccion, estas hembras pueden obtener en la siguiente muda una condicion morfologica semejante a la joven, como fue verificado en condiciones de laboratorio controladas. La obtencion del reposo sexual divide a las hembras de talla puberal en rectas de regresion distintas, por lo que las estimativas de talla a la maturidad sexual atraves del analisis del crecimiento alometrico del abdomen son inadequadas para esta especie.

Mortality and breeding failure of little penguins, Eudyptula minor, in Victoria, 1995 - 96, following a widespread mortality of pilchard, Sardinops sagax

2000 ◽  
Vol 51 (4) ◽  
pp. 355 ◽  
Author(s):  
Peter Dann ◽  
F. I. Norman ◽  
J. M. Cullen ◽  
F. J. Neira ◽  
A. Chiaradia
Keyword(s):  
At Risk ◽  
Breeding Season ◽  
Breeding Success ◽  
Egg Laying ◽  
First Year ◽  
Breeding Failure ◽  
Food Species ◽  
Intestinal Parasitism ◽  
Western Victoria

In May 1995, numbers of little penguins, Eudyptula minor, coming ashore declined at Phillip Island and St Kilda concurrently with deaths of many penguins in western Victoria and a massive mortality of one of their food species (pilchard) throughout southern Australia. Among 1926 dead penguins reported were 131 banded birdsrecovered from Phillip Island (86% adults and 14% first-year birds), 26 from Rabbit Island and six from St Kilda. The number of banded penguins found dead per number of adult Phillip Island birds at risk was 2.3% in 1995 compared with an annual mean of 0.7% for 1970–93. Of 29 corpses autopsied, at least 26 died of starvation associated with mild–severe gastro-intestinal parasitism. Following the pilchard mortality, egg-laying by penguins in the subsequent breeding season (1995–96) was ~2 weeks later than the long-term mean and 0.3 chicks were fledged per pair compared with the long-term mean of 1.0. Unlike previous years, few penguins were recorded in Port Phillip Bay in September–October 1995, a period when pilchard schools were infrequently seen. It is concluded that the increase in penguin mortality in northern Bass Strait and the significant reduction in breeding success were associated with the widespread pilchard mortality.

Regional divergence and inbreeding in Eucalyptus cladocalyx (Myrtaceae)

2003 ◽  
Vol 51 (4) ◽  
pp. 393 ◽  
Author(s):  
M. W. McDonald ◽  
M. Rawlings ◽  
P. A. Butcher ◽  
J. C. Bell
Keyword(s):  
Genetic Diversity ◽  
Natural Populations ◽  
South Australia ◽  
Natural Distribution ◽  
Flinders Ranges ◽  
Outcrossing Rates ◽  
Low Levels ◽  
Western Victoria ◽  
Ornamental Species ◽  
Regional Divergence

Eucalyptus cladocalyx F.Muell. is a widely cultivated tree in dryland southern Australia. It is grown for firewood, timber production and as a windbreak and ornamental species. Natural populations of E. cladocalyx are endemic to South Australia where they occur in three disjunct regions. This study assessed the mating system and patterns of genetic diversity in natural populations of E. cladocalyx by using allozymes. Populations had relatively low levels of genetic diversity (HE = 0.148) and high levels of genetic divergence (θ = 0.26) among populations, similar to other regionally distributed eucalypts. Populations clustered into three distinct groups, which corresponded to its disjunct natural distribution. Genetic differentiation among populations and between regions was highly significant. Relatively high levels of inbreeding (tm = 0.57) were detected in natural populations of E.�cladocalyx. Outcrossing rates were highly variable among families, ranging from 0 to 100%. One-third of families from four populations had outcrossing rates that were not significantly different from zero. The origins of three commercially significant, cultivated stands of E. cladocalyx were also assessed. Allozyme profiles of cultivated stands from Wail and Lismore in western Victoria suggested origins in the Wirrabara region of the southern Flinders Ranges, while a cultivated stand of E. cladocalyx var. nana Hort. ex Yates had an allozyme profile consistent with origins in the Eyre Peninsula region. The results are discussed in relation to the species' morphological variation, biogeography and the implications for its domestication and conservation.

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